C. Hong, Y. Kishi
Aug 1, 1992
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0
Influential Citations
49
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Journal
ChemInform
Abstract
An enantioselective total synthesis of (-)-decarbamoylsaxitoxin (2) has been accomplished, using the asymmetric trimolecular cyclization of 6, i.e., 6 + (R)-glyceraldehyde 2,3-acetonide + Si(NCS) 4 → α-7, as the key step. The structure of the major product α-7 was determined by X-ray crystallographic analysis, with the C-6 configuration corresponding to the unnatural antipode of decarbamoylsaxitoxin. Acetonide α-7 was converted to thiourea 5, an intermediate used in our previous racemic synthesis of saxitoxin. Thiourea 5 was further transformed to the tricyclic urea-thiourea 3